The invention relates to a method and apparatus for packaging chunky product or articles, such as cheese, in reclosable zipper equipped packages and is more particularly concerned with a mechanical arrangement for feeding package wrapper material to a production line in a manner which prepares the wrapper material for reception of product in a reliable and expedient manner even at high production speeds.
Commonly assigned U.S. Ser. No. 547,392, now U.S. Pat. No. 4589145, filed Oct. 31, 1983, and entitled "Method Of Packaging, Packaging Material Therefor And Package", concerns the use of zipper equipped sheet material for producing a package in a conventional horizontal form, fill and seal machine such that the package can be reclosed after access has been gained to the product in the package. The special zipper equipped material comprises a wrapper sheet having a panel area for engagement with a face of the product, the sheet having portions which extend beyond the panel area and which are adapted to be wrapped into an envelope about the product by folding the sheet portions about the product edges and into engagement with the other face of the product. The free margins of the sheet portions are secured into a seam at the other face of the product and the wrapper sheet is dimensioned to provide for cross-seals at the ends of the envelope. The reclosable zipper means are provided on one of the sheet portions for closing together a web fold on that sheet portion. The web fold is adapted to be severed or ruptured to provide a package mouth opening for access to the product in the envelope, the mouth opening being reclosable by means of the zipper.
Plastic zipper bags equipped with cooperating reclosable fastener strips disposed along one edge of the bag forming a bag mouth have been known for a long time and are widely used both for commercially packaged products. Unfilled zipper bags have been supplied in large numbers for household use as sandwich bags and the like. However, Ser. No. 547,392 is understood to represent the first recognition of producing a package on a conventional horizontal form, fill, and seal machine wherein the package is equipped with zipper means so that the package can be reclosed after access has been gained to the product in the package.
A large volume of products of a relatively chunky, heavy type, such as bulk or sliced cheese food products, have been packaged in horizontal form, fill, and seal machines. The only type of packaging effected by these horizontal form, fill, and seal machines has involved wrapping of sheet packaging material about the product and sealing along a longitudinal line and then cross-sealing to complete the package. U.S. Pat. No. 3,274,746 is representative of previously existing conventional horizontal form, fill, and seal apparatus for packaging relatively heavy articles such as cheese in plastic film or the like. The method there disclosed consists of running the wrapper sheet in the form of a continuous strip along a horizontal packaging line wherein the wrapper sheet is wrapped about the product articles successively placed thereon in spaced units by folding the sheet from opposite sides onto the articles and sealing the opposite longitudinal margins of the sheets together. The sheet is, in effect, sealed into a tubular envelope about the articles and subsequently sealed across the envelope between the articles and separated into sealed individual article-containing package units. Such conventional horizontal form, fill, and seal apparatus is adapted to operate at relatively high production speeds in a continuous fashion.
The present invention concerns novel method and apparatus for bringing about a reliable and continuous feeding and opening of zipper equipped sheet material to be used for packaging products of a relatively chunky, heavy type, such as bulk or sliced cheese, so as to prepare the sheet material wrapper for reception of product and subsequent wrapping of the product in a conventional form, fill, and seal machine. The invention enables the conventional form, fill and seal machine to operate in its previous continuous, high-speed fashion even though the machine is now handling a very different zipper equipped wrapper material rather than conventional and intended continuous, flat wrapper sheet.